1. Field of the Invention
The present invention relates to vehicle seats and to seat recliner mechanisms therefor. More particularly, the present invention relates to an adjustment mechanism which allows for adjusting of the seat back with respect to the seat cushion.
2. Description of the Prior Art
The prior art is replete with various forms of such seat recliner mechanisms and may be generally described as complex and possibly susceptible to accidental disengagement in an accident mode. Examples of such typical prior art are the following U.S. Pat. Nos. 3,508,294; 3,673,891; 3,840,268; 3,893,206; 3,902,757; 3,973,288 and 4,035,866. German Pat. Nos. 2,328,908 and 2,414,910 are also typical of the above class of seat recliner mechanisms.
U.S. Pat. No. 3,902,757 and German Pat. No. 2,414,910 show seat recliner mechanisms having hinge fittings for an adjustable back seat comprising a first plate fixed to a back rest and a second plate fixed to a cushion. The plates form recesses and a ratchet in the form of turnable disc. The ratchet is peripherally toothed and may be brought into engagement with the recesses. The ratchet is supported so that it can be turned and has a radial slot which engages a pin fixed to the seat for locking the back rest into position.
U.S. Pat. No. 3,840,268 shows an adjustable back rest having a first part with a fixed set of teeth and a pivotable second part with a second set of teeth. The second part moves transversely relative to the fixed set of teeth by camming means with an operating handle to engage and disengage both sets of teeth.
Finally, German Pat. No. 2,328,908 shows a fixed fitting on a seat cushion and pivoting fitting fixed to the seat back. The pivoting fitting moves on a common axis with the seat back. It is held in position by a two-armed spring loaded pawl or latch. The pivot has bolts fitting onto the other plate and anchor hooks on the opposite side of the arms of the latch. The latch being operated by a hand lever or cable.
These patents illustrate the general state of the art and are believed to be workable embodiments of the prior art seat recliner mechanisms which would perform marginally at best and in the passenger vehicle environment. Not only are these prior art forms of seat recliner mechanisms complex utilizing multitudinous interacting parts which may malfunction in operation but further involving substantial weight penalty. It is with the basic problems of reliability and weight that the present invention was conceived.